Location data from a mobile device can be used for numerous applications. Many applications, for example, use location data for locating friends, playing games, and assisting a user with directions. The location data can also be used to provide an alert on a user's mobile device when the user is the vicinity of a point of interest, such as a business, an institution, landmark, park, or other location that would be of interest to a user. For example, a user may choose to be alerted every time the user is near a particular store or restaurant, especially if the alert includes a promotional offer for the store or restaurant of interest.
While location data can be used for a variety of applications, efficiently obtaining location data from a user device can be challenging—especially when accurate location information is needed. Conventionally, to obtain location information for nearby locations, the user device periodically scans its environment for available wireless signals every few minutes. The user device then communicates the location data to a location-based service, for example, which then determines the location of the user device by recognizing the available wireless signals.
Such periodic scanning for wireless signals, however, drains the battery life of the user device, as does the communication of the location data to the location-based service. The periodic scanning for available wireless signals is particularly wasteful of battery life, for example, when the user device is not near a point of interest. For example, a user may be carrying the user device while hiking in a wilderness remote area. Nevertheless, the user device may continue its periodic scanning for available wireless signals (even though none exist in the area).